Locking mechanism for impulse-transmitters.



c. L.v GoonnruM. y Lo'cK'lNG MEcHAImsM Fon IMPuLsE mArsMlTTERs. y

APPucATloN mw MY 1. 1909.

Patented Apr. 24,1917."

` paniers-SHEET an UNITED STATES PATENT OFFICE.

CHARLES L. GOODRUM, OF URBANA, OHIO, ASSIGNOR, EY MESNE ASSIGNMENTS. TO WESTERN ELECTRIC COMPANY, INCORPORATED, A COLP'ORATION OF NEW YORK.

LOCKING MECHANISM FOR IMPULSE-TRANSMITTERS Specification of Letters Patent.

Patented Ap1'.24, '1917.

Application led May 1, 1909. Serial No` 4 `93,395.

To all lwhom z't may concern.'

Be 1t known that'I, CHARLES L. GoonRUM,

a citizen of the United States, residing at Urbana, in. the county of Charnpai and StateY of Ohio, have invented certain new and useful Improvements in Locking Mechanism for Impulse-Transmitters, of which associations.'

The 'object offm invention is to provide means for automatically' locking an lmp'ulse transmitter or `aling-.devicegiirlie' never'the circuit over whiehzstheimpulaesa to be transmitted' i8" lebeilid retaining the saine-locked until suc atimegastlie circuit is in proper' condition to .receive such i 1 npuls es s, station-thus' placing the application `te' th Called' subscriber@ line under Ithe direct` 4the mitter a'dap 'to rbe operatedf transmitter by electricall operatedidevices softhatxwhen-'afcunfent o a" proper: strength to give-effect tothe'impulses tof-jbe tra-nsmitted lthro'ughfs'tlie impulse j initter, t e saiddevi'ce willfbeunlocked, the constructionbeing sueh'-that under an'yfother condition the" impulse 'traiisniitter'- wil1 be locked against .operationf "Whenf'the im; pulse transmitter 1s connected to theswtch. lng or receiving devices,V (such as' a, selector or connector switch) ,"-the '(:lfirre'ntiloivin v, in

4the circuit will vbe' of .suiiicient `strengt 'to 'unlock the transmitterfsothatt can be used to transmit impulses to the oiiice switches to het' u the. connection. After .the' connection has n' -extendedthrough; the` switches, t0 bclibrs .line the iinpulsetransmltter reuflanf enhloclrectv operation et :he impulse transmitter. after the connectioi llas'been extended to the' called subscribers line. will connect ringingr current to the line of the called subscriber.

In the accompanying drawings I liav illust-rated my invention in connection with circuits of an lutomatic telephone exchange, the arrangementsbeing such that-the impulse transmitter will belocked until the apparatus to be acted upon by said impulse transmitter is broughtinto circuit.

In the said drawings. Figure 1 is a diagrammatic vieu' illustrating a single calling station in connection with automatic switching mechanism, (such as is generally knqwn as a finder swi .ch) with the apparatus necessary to 'cut through the lines from the. calling station to,4 the apparatus, (such as a sclector' or connector switch) which would be gperated upor by Vthe impulse transmitter.

ig. -2 is a Vdia grammaticviea' illustrating a subscribersjstation 'and' showin`g-the mechanical arran gement of the locking devices .fer a 'calling-1 Avice having a rotating dial. lis a; agrammatic viewl of a called F" 's tiioli'showin'g'thearrangement of a part of- Vthe 'exc'hang lienaechanism .used in connection with the swithfing mechanism for s i heling and'-foi-:releasing-thelines alrea y connected..

In'the diag1amnia'ticvew Fig. 1, I have 'shownjthefsimjplestjorm of circuit, ,one callringitsubwiberfm' vcntion-'consistsprimailygigan `imwithfits a proved lot. 'L Vdevice-for-an .impulseltrans unloej'kpthe 'r.. I

aneraofwine i automatic, switching depanying relayv apparatus seleoto'oronneetor switch, naylejused in. connection the 'impu lsetransmitter.

Like. 'characi ers 1 of v 'reference indicate like .the Saidilg'lrawings, A represents a call-- ing f sub-statin;4 -B. represents the' automatic switching .mechanlsn1,. and C represents' a eall'edstation.. Atthe stati(4 11, A, in Fig'. 1, I have illustrated onljthc signaling orfmpulse mecha` .'lipefthrough to L'called mitter which lnay consist of a metallic disk having a portion. (1.1, thereof of insulating material adapted to be revolved so as to conltact with wi )ei-s. a a3, which are arranged receiver hook, as, is adapted in the usual4 manner, when the receiver is removed, to make connection with the line. l, which, with .its mate, m, constitutes the subscribers line to the central station. A circuit is established from through the receiver hook, a, by wire 1 (one), through wipers, ft2 a, and thence by line 3 to mate m. The line, l, and its mate, m, terminate on contact l1 and m1, it being understood that there would be similar contacts for each subscribcrs line which enters the'exchange and common to the same switching mechanism. Each. 'subscribers line is provided at the central exchange with aV line rela-y, c." and a 'cut-off relay,' d, and

when the circuit is closed at a subscribers thrown directly on the line and station by operating,r the receiver hook, a, a

circuit is established through the line relay, c, as follows: from the hook, a", through the line Z,wire 4, circuit breaker, (l1, Contact, cl2, Wire 5, to one side of coil c, thence through wire 6, battery "v, wire 8,' the opposite side of coil c, WireJ 9, contact el", circuit breaker` (1", wire 10 tothe opposite side or mate, m, of the line.

In this particular adaptation of my locking device the battery, 7 of, say,20 volts, .is not of sufficient potential to operate the re lay, a', although this battery is, by the operation of the closing of the circuit `ust named,

through the coil, a. The battery, 7, however,is'sui ciently strong tooperate the relay, -c',which causes it to pull up .its armature and close a circuit as follows: from ground atv ci,

through circuit breaker lc?, contact c, wire 11, switchl arm 12, contact 13,-' wire I4, -con- ,tact 15,.. .arm V16,'line 17, to relays wire 18,

battery 20 and'to ground Vat el. T. e battery 20 is of much higherpotential than the baft tery 7, being preferably about 60 .yolts, and

:is the battery'usedl for operating the. switch ing apparatus at the exchange and also for supplying talkingfcurrent.

,tracedv will energizethe relay, e. The efect .of energizing the relay. e` 1s to close 'the cir- Tlie circuit just cuit breakers. c and e. The closin of the circuit .,liifealter', e2, establishes the 'folowing circuitfrom ground at 2.1,.tl1rough Wire 22, contact k", circuit breaker'k, wire 2 5, branch 26. circuit breaker. e2, contact. e, wire 27, wire 74, to relayf, wire 34, wire 35, wire 36,

battery Q0 and to ground :it cl. This energizes the relay. and establishes a circuit as follows: ground at 3T. wirtI 3H. circuit breaker j". contact wire 255i, circuit breaker c. contact ci'. wire 40. wire 41, to motor magnet wire 42. battery 3. wire +4. to ground at t5. A branch circuit is also established from wiie l0. by wire 46. to relay L, wire 4i', and thence by wire 35 and wire 3G to battery Q() and ground at c. thus energizing t-he magnets f/ and h. The magnet, g. is the motor magnety tor operating the switching mechanism which is to -connect with the calling subscribefs line and which would be known as a finder switch.

The energizing of the magnet, y. breaks the circuit of tht` relay. c. at the contacts. 15 and 16. it also moves the operating spring for the switching mechanism back one notch. The. circuit for the motor magnet. y. however. passes through the circuit breaking contacts. c" c". so that when the magnet. c. is deinergized it. in turn. deinergizes the motor magnet. y. which permits the step-up devices to move the nder switch one step. The relays. f and z. are what are known as slow relays and their operation is retarded so that if the denergiz'ing. of the relays. c

and y. is quickly followed'by closing their circuits andenergizing thesame. the magnets, f and i. will not-become Adeinergized but will hold over. holding their armature contacts in the position assumed by them-by reason of the electro-inagnetic force of the relays.

It will he understood that each step of the Y v.closed by a projection, b. on the switching mechanism. but at the first step of said switching device this projection, .1, moves away from the arm. 12. and opens the-icon,-- tacts at 12 and 13'. so that :the further operation of the relay, e. must be attained by cui rent secured from some. other source. which I will now proceed to describe.` The finderswitch is preferably provided with four arms or wipers,^b1. b, 11. the wipers, b1 and are adapted to contactwith the terminals, l and m1., of thelines-and n .iates-'of the respective subscribers.. and the 'wiper-"saw and b, are adapted to contactwith lterminalsof local op erut in ,circuits to be described. Thesewipers wil preferably be placed .one

Aabove the other on afvertical=laxis, lbeing I have .shown one set of terminals only which contact with the wipers, b3 and b, and these are c and d, .it being understood that there will be a set oliytermiualsyl c d, for each set of line terminals, l? and m1. Assuming nowthat 4theV finder' switch -has stepped upone stepand the.wiper, b, has (gontainedwith the terminals, o, on a line Whose relay, has not ybeen operated, 4a circuit may then be traced'f-rom ground c1, through circuit breaker of," contact c, wire 48, to terminal c, wiper 6*, line 49, wire 25, circuit breaker; k1, Y(the relay, h, being held u p) contact, h wire 5.1wire 14, contact 15, circuit breaker 16, wire 17, relay wire 18, battery 20, to ground. Thus, again energizing the relay, e, which would repeat the operation fof energizing the motor magnet, g, whichin turn breaks the circuit of the relay, e, at, .15 and 16, causing the said relay to be denergized, thus denergizing the motor ma" et, g, and causing the finder switch to in e another'step. This operation will be continued so long as the wiper, b, continues to'iind oundi through the'circuit, as indicated by wire 48. circuit breakers, c2 c, and ground at c1, TVheu, however, the circuit at cc is broker, as it will be whenever the line relay, c, of any subscribers line is energized, then the, wiper, b4, will not find ground and 'the relay, c, will not be energized and the finder switch will, therefore, stop on that line, thus connecting the subacribers` lines, Z and m, through terminalsJ1 and mi, to wipers, b b2', and thence by wires,

l and m2. The line, Z2, p'asses through con! tact, 52, circuit breuken-53, and out to the. calledstation or to some other switcbingevice, such. asa selector or connector switch, while the line, m2, passes through contact,

54, circuit breaker 5 5, in a similarway tothe cal'ledfstation or some other switching device. From l a branch, 56,- leads through n relay, j, bywire, 57, to ground at ji.. A branch, 58, from m? passes -through the other coil of the relay, j, thenceby wire, 59, of wire,=36, to battery w and to ground at c. Thisl throws the high potential battery, 20,

directly on the subscribers line. `The circuit.

may be traced from ground at c1, battery 20, wire 19, wire 36,' Wire 59, one side Vof the` relay, j, wire 58,4 to one side of the line m2,

thence through the wiper, b1, terminal lmi,

`line m, :lock coil, ai, at the calling sub-` scribers station, two wipers a? a3,- impulse device al, line l, receiver hook, a, line Z.terminal l, wiper b, line lbranch- 56 other side of the relay and to ground at j, the `battery 20 being of suiieent voltage to operate 'the lock coil, ai, the lock lever.' a", is rcmoved from the dial, a, and the transmitting device is ready for operation.

The moment that the wiper', b, fails to find ground upon" the terminal, c5, as before described, theV wiper, b, contacts with the terminal, d?, 1nd closes the'cireuitas folbattery T. wire (i1. relay terminal r/ wiper bf, line 6:2. contact (i3, circuit breaker f1, line 3S and to ground at 37. This energizes the relay. (I. and cuts off both sides of the coil of the line relay. c. the circuits for which pass th 'ough the circuit breakers. rl, (l2, (Z3. fl* as heretofore described, thus cutting out the relay, c, from the line and lea ving the relay. energized so long as the wipers. b3. remain on contact,-(5. A

In the descliption thus far it is assumed that the'lines. Z2 and vnf-, are to be connected withthe devicfs to which impulses are to be t-ransn'litted. The impulse transmitter at the calling stai ion is now free to be operated and'may be oerated in such manner as is necessary, eit 1er to establish connection through other suitable switching mechanism with. the subs( riber or to send signals to a. station which may be connected directly on the lilies, Z2 and m2. In releasing the line the Subscriber at ,L hangsl up the receiver which breaks the cornection between the receiver hook,(r.",` and line. Z. This breaks the circuit, previousLv described. (Fig. 1) through the relay. y'. which causes it to be .deneroperated there by, closes against the contact jvestablishing' the following circuit: from ground at 64. through circuit breaker ji, contact 53. Vwhe 65. circuit breaker lgcontact h, line 63 contact 6T, circuit breaker 68, wire 69 release magnet l', wire 70. battery 43. wire 44. to ground-at 45. VThis release magnet, i', becomes thus energized and its armature is arranged to disengage the pawls, the hol ling pawl ,and the operating pawl on the fnd'ervswitch thus permitting said switch torreturn to its normal position. The energizing,l of themagnet. also closes the following circuit: from grou-nd at 71, contact- 72. `circuit breaker T3. hline" 74, through relay f, wire 34wires 35, 3G. battery 20 to grornd at b1. This opens the line contacts. 52, 5H. 54,55, so as to preventthe wipers from tilding ground in passing over the contacts ou their return to normal. In returning to normal thecontact, on the switching devi :e operates the circuit breakers, 12 and 67, to close the circuit at 13 and break the circuit at (3T. thus deenergizing the magnet, lo, anl restoring -the starting cir cuit' for the relay. e.

Assuming the line. Z2, is now connected either to a called station by means of an in.-

ftermediate sw'i rhing device or direct, I will the callin ular manner. The line, m, will be connected througlfthe circuit; breaker, n, n, to line, m3,. in a similar manner.

Then thisI form of ringing circuit is employed the circuits for the relay j in Fig. 1 and the release circuit controlled thereby are modified as shown in Fig. 3. in which the rela v corresponding to j, is marked f. The release circuit (l5 is passed through contact p" and spring [1 ot' a relay p. the release circuit in this case being from wire 433. contacts p, IF. wire T). to contactsl I and z-' (which correspond with i" and jl' in Fig. l), and thence by wire. T5 to ground. The relay 71 is controlled b v the forward contact. of relay, t, (j in Fig. 1), and when said relay-is energized it energizes relay p over the circuit from jrround'by wire T5'. spring;r f". contact fl. wire- Tl, rela)v [1, wire ii. battery 2U. and wire. TS to ground at I, 'l`he relay /1 is a slow relay and when energixed. breaks the release circuit atp and closes its spring; /F- against the contact p. This closes the circuitfor relay n through wire Hl). relay n. wire- TT, battery Q0. wire T8. wire Tfn .spring f2, contact f". and wire T0 to spring lc'. When relay t is energized therefore. relay p will be energized and the circuit thereby closed at contact t. AYhen rela)Y t is deenergized. relav -nA will be energized over the circuit closed at, back contact f", providing,r that the springr 7F is on the -tront contact p1. Relays p and n vare both slow relays so that relay y) will hold up momentaril' after relay is deiinergizcd, which permits'relay -n to receive current hy denergizing relay and before relay p allows its armature to drop back. Ina-smuch asrelay t is a normal relay which will respond to impulses of current, its armature will alternately open and close the circuit-s for relays?, and -n at theback and frontcontactspf' and p4, a series of impulses over lines Z2, m2, will keep both of these relays p andn enereized. release circuit to lie broken at. p3 and cause ringing circuitto be applied to the calledstat-ion whenever the impulse transmitter at station A is operated. These-impulses wi 4have the effect of energizing the slow relays?) and n, and holding their ar matures," and closing the circuit breakers, n2 and nf", on the cont-acts, nl and n, which contacts are the terminalsfor the opposite sides of 'a generator circuit, as indicated at r. The result will be thatso long as the impulses continue .and the relays, n and 71, continue to hold up, thegenerator will be included in' timeline-Z3 and m3,'and will cause the-signaling' device, 0,-to be operated and also', as soonjfa-sthe impulses cease, the relay',

t, wat be @gramm-r Zed, which will bred-kthe"circuits'tothe reay, n, causingi it to be energized and interrupt' the ringing cirf .When the calling subscriber breaks the This will cause the' -nism fo'r establishin .connection between the same 1nvol\' 1-ng.-a c a ling station and al1-ini,-

circuit atthe receiver hook. a, the magnet, z-, is deiinergized. which, in turn. decnergizes the magnet, p. and closes thc release circuit, heretofore described. fromthe .line (35, through the craitacts. and j. line Til. c011- tacts f and I". and wire T5 to groumLt-he 1 -ela v p. and the additional circuit breaker in the release circuit being' provided so that the release magnet shall not be operated-by the vibratimis of the circuit breaker. ff'. .caused by the impulses'on the line by the iin-pulse transmitter.

ln practice all the circuits here. will be metallic circuits and where ground isieferred to it is to be understood that this indi-l cates simply one terminal. of the battery which will be connected by -metallic circuiteither b v va suitable battery wire or common return.

llaving thus described my claim:

1. The combination with an impulse transmitter. a normallyv open subscriber-s line into which said transmitter may be ineluded. a locking device for the transmitter. an electromagnet adapted to be connecte-d into the subscribers line foropera'ting the said locking device to unlock the transmit ter. an impulse receiver` and, means. for establishing a connection with said impulse receiver upon closing thev s i-ibscribei-*s line, -a soiirce ofelectric energysuflicient to, operate the electromagnet tounlock sai-d transmitter. and means for connecting` said-'energy onto the subscrihers line when' theimpulse eceirer in circuit, substantially as speci- In an automaticl telephone system, a

invention. I

calling subscribers station, a.n automaticr slow acting relay and a generatorcircuit normally disconnected from.' but-adaptedf-to be connected with, said ca-lledsubscribers line b v-said slow acting relayv influenced-by the impulses from said-transmitter, whereby ringing impulses may besent from :said f transmitter after connect-ions have'beenestablished between the calling and called sub,- scribers stations. M 3-.i-Ih an automatic 'teachers-System, -tw subscribers stations, an automatic mechapulse transmitter, means forv establishmg; Seid! nneetipn.- `byimpulses. fram; Said transmitter-, a. generator, 'circuit -ixormalljr dlsconnected from connected stations, a,

'generator circuit into the connected linev relay responsive to interruptions in the line ci'rcult,y a slow relay, and a rmgmg relay,`

said .ringing relay being controlled jointly by said line and slow relays to connect said 'generator circuit into the connected line circuit.

5. In an automatic 'telephone system, two subscribers stations connected for conversation, a ringer at one of said stations and an impulse transmitter at the other, a n or-A mal relay bridged on the line and having back and -front contacts respectively connected in 'circuits with two SlowV relays, one'l of which relays 'controls a ringing circuit and being in turn controlled by the other relay whereby` the vibration of thearmature caused by impulses through said nor1nal`re lay will hold up the two slow relays and thus cause rill ging current to, be applied to the 'called station so long as impulses of cur- .rent are passing through the normal relay.

G. In a sigraling system, the combination of a line rela v, an interrupter foi-controlling the actuation of said line relay,- a sl0\v, acting relay rnder the control of said line relay and a ringing relay under the control of said slow-a :ting relay and Said line relay.

7. In a sign aling system, the combination of a line rela v, an interruptor for causing said line relay to vibrate, a slow-acting rela-y having a circi it closed in the actuated position of said llne relay and a ringing relay haring a closed' circuit in the actuated position 0f said slow-acting relay and the nor` mal. position f f said line relay,

.In testimonyv whereofv` I have hereunto set my hand this lGth day of April, 1909.

SHAB-LES L. GOODRUM. 

